Preheat your oven to 350°F and line a small loaf pan with parchment paper.
Whisk almond flour, flaxseed, salt, and baking soda in a large bowl.
In another bowl, beat the eggs, then add vinegar and melted butter.
Stir the wet ingredients into the dry. Mix just until everything's combined.
Pour the batter into the prepared loaf pan and smooth out the top.
Bake for about 40 minutes, until the top is golden and a toothpick comes out clean.
Let the bread cool in the pan for 10 minutes, then move it to a wire rack to cool completely.